1 / 19

Influence of ENSO on European Climate via the Stratosphere

Influence of ENSO on European Climate via the Stratosphere. Sarah Ineson and Adam Scaife 2007. Stratospheric response to El Ni ñ o. Hamilton, 1993. Impact of 1940-42 El Ni ñ o on Europe. Br ö nnimann et al., 2004. Experiment design. L60 HadGAM1 with observed SST 4-member ensemble

tanek
Download Presentation

Influence of ENSO on European Climate via the Stratosphere

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Influence of ENSO on European Climate via the Stratosphere Sarah Ineson and Adam Scaife 2007

  2. Stratospheric response to El Niño Hamilton, 1993

  3. Impact of 1940-42 El Niño on Europe Brönnimann et al., 2004

  4. Experiment design • L60 HadGAM1 with observed SST • 4-member ensemble • 1960-2002 • ENSO based on DJF Niño3 SST anomaly: Warm: 1965/66, 72/73, 82/83, 86/87, 91/92, 97/98 Cold: 1967/68, 70/71, 73/74, 75/76, 84/85, 88/89, 99/00 • warm (cold) years – neutral years

  5. DJF stationary wave anomaly at 50°N L60 HadGAM1 MA-ECHAM5 ERA40 Manzini et al., 2006

  6. Model vs observed response to warm ENSO events DJF geopotential height, Z, 46hPa Model Observations (Hamilton, 1993)

  7. Downward progression L60 HadGAM Manzini et al., 2006

  8. Composite model surface response to El Niño Jan-Feb PMSL Jan-Feb T2m

  9. Intra-seasonal variability: PMSL Nov Dec Jan Feb Moron and Gouirand, IJC, 2003 The negative NAO signal appears in late winter in both model and obs.

  10. Intra-seasonal variability: T2m Nov Dec Jan Feb Mar Apr Corresponding cold European signal in late winter, persists into Spring

  11. L38 HadGAM1 vs L60 HadGAM1 vertical resolution

  12. High Lid – Low Lid HadGAM1 comparison DJF Z46hPa composite for El Niño events, 1982/83, 1986/87, 1991/92, 1997/98 L60 HadGAM1 L38 HadGAM1 (standard resolution)

  13. High Lid - Low Lid HadGAM1 comparison Jan-Feb PMSL composite for El Niño events, 1982/83, 86/87, 91/92, 97/98 L60 HadGAM1 L38 HadGAM1 (standard resolution)

  14. Summary of mechanism • Model reproduces observed infilling of the stratospheric polar cyclone associated with El Niño • Better stratospheric response in L60 than L38 model • Negative NAO and cold European surface response in later winter as in observations • Potential increased capability in seasonal prediction for Europe in winter

  15. DJF stationary eddy height anomaly at 500hPa L60 HadGAM1 MA-ECHAM5 ERA40 Manzini et al., 2006

  16. Model NH stratospheric response to QBO U46 hPa (10°N -10°S) Z46 hPa +ve QBO -ve QBO

  17. Model response to warm and cold ENSO composites DJF geopotential height, Z, 46hPa Warm Cold

  18. (a) (a) (a) (b) (b) (b) (c) (c) (c) Figure 3. January MSLP response for (a) ELN – CTRL for standard stratosphere, (b) ELN –CTRL for degraded stratosphere and (c) the difference between the responses due to the inclusion of stratospheric variability. Units are in hPa. Figure 3. January MSLP response for (a) ELN – CTRL for standard stratosphere, (b) ELN –CTRL for degraded stratosphere and (c) the difference between the responses due to the inclusion of stratospheric variability. Units are in hPa. Figure 3. January MSLP response for (a) ELN – CTRL for standard stratosphere, (b) ELN –CTRL for degraded stratosphere and (c) the difference between the responses due to the inclusion of stratospheric variability. Units are in hPa. ENSO teleconnections in European winter Chris Bell and Lesley Gray, University of Reading standard stratosphere degraded stratosphere

  19. Impact of El Niño on North Atlantic climate January-February PMSL anomaly Strong Moderate Toniazzo and Scaife, 2006

More Related